CVE-2026-44723: Vowpal Wabbit: Unrestricted System Command Execution

Summary

The Vowpal Wabbit workflow on GitHub Actions allows an attacker to run arbitrary system commands when a pull request is made. This can happen when a malicious user creates a pull request with a specially crafted title. To fix this issue, update the workflow to prevent the shell from interpreting the pull request title as a command.

What to do

No fix is available yet. Check with your software vendor for updates.

Affected software

Vendor	Product	Affected versions
vowpalwabbit	vowpal_wabbit	< 2026-05-04 `cpe:2.3:a:vowpalwabbit:vowpal_wabbit::::::::`

Original title

Vowpal Wabbit is a machine learning system. The workflow .github/workflows/python_checks.yml embeds ${{ github.event.pull_request.title }} directly inside double-quoted bash strings in four separat...

Original description

Vowpal Wabbit is a machine learning system. The workflow .github/workflows/python_checks.yml embeds ${{ github.event.pull_request.title }} directly inside double-quoted bash strings in four separate steps across four jobs, each passing it as a CLI argument to the Python test script run_tests_model_gen_and_load.py. The shell interprets the expanded string before invoking Python, allowing an attacker to break out of the quotes and execute arbitrary commands on the runner. The pull_request trigger fires on PRs targeting any branch (branches: ['*']), with no additional access gate. This vulnerability is fixed by the 998e390e80a7e8192d7849b7784bc113dbd190ad commit.

nvd CVSS3.1 5.0

Vulnerability type

CWE-78 OS Command Injection

CWE-1336